Psychology is a strange profession. I am including psychiatry in my meaning of the word psychology for this blog, just by the way.
Because every person who delved into the world of Psychology was looking at everything from a - shall we say, limiting - view point, the resulting theories and assumptions are based on incomplete and sometimes deeply flawed knowledge and understanding. This obviously means that nothing that any psychologist has ever said can be trusted - simply because they were simply following their preprogrammed design. The system guides us all very well to live in a certain way, believe certain things, like certain things, dislike certain things...
There are occasional glimmers of potential in these theories. For example, there is a school of thought within psychology that we are the products of our environments - which actually makes sense without having to justify and logickify. Unfortunately, it is surrounded by a load of dribble as well and seems to focus on using this concept to enlighten and improve on the lives of the well-off - it does not even go anywhere close to developing solutions to the obvious social dementia that is going on in the world (rape, murder, profit over life - you know, the things we now, through generations of conditioning, believe are simply a part of life that cannot be changed).
Currently, most psychologists agree that abnormal behaviour (craziness) is the product of multiple factors and not just one, as was previously believed. So now, there are a bunch of theories that propose that a combination of this, that and that produces a crazy person. All that this shows us is that psychologists have absolutely no clue how and why human behaviour develops the way it does. Psychology textbooks are filled with if's and show no comprehension, or even curiosity as to how the human mind really works. Opinions matter more to psychologists than the truth.
If Psychology was valid, there would be no disagreement over treatment methods. If Psychology was valid there would be a consensus among psychologists as to how human behaviour develops. If Psychology was valid then it would be a priority to find out how the human mind works and how to correct abusive or "abnormal" behaviour. If Psychology was valid, there would be only one school of thought: the truth.